So, I am new to here and I am currently a technician that does vacuum systems for the semiconductor industry (mainly Electrical). I came across something today that has me quite perplexed. So We have this system that flows gas through 1/4" stainless tubing to a pump to dilute gasses and chemicals inside. For testing purposes we run compressed air just to cool the seals. From my understanding the fabs run N2 through them for purge. My issue is that some systems we get good flow rate through at 6-9 SLM. others will flow lower. Our alarm for the flow is 5 SLM but our flow averages between 5.4 and 6.4 SLM. I think our specs are wrong as we have to make them because there is no manual for these pumps that is in English. Another tech says it's the solenoid that restricts the flow through the line set. When you look up the spec for flow rate on the solenoid it gives you 0.27CV. If I convert this to scfm at 90 and 100 psi I get a minimum flow rate of 14.0625 SCFM and a max of 15.2542 SCFM. We do not use SCFM so when I convert that to SLPM I get minimum of 398.21 SLPM and max of 431.95 SLPM which indicates that this specific solenoid does not restric our max flow which in the system is 60 SLPM. Does this sound legitimate? I have read that there is no pressure and flow relationship but I don't quite understand why.. I would think that more pressure would increase flow in a closed system like this because higher pressure=higher pressure differential between input and output. Basically put I am trying to confirm that this solenoid has no way of restricting this flow rate lower than the 60 SLM. How would I legitimately go about figuring out the flow rate of this Solenoid?